There are certain colors that the RGB model uses that fall outside of the color ‘gamut’ capable with CMYK.
Print resolution dpi
Dpi, or dots per inch, refers to the number of dots printed in a linear inch. The pixel dimensions of your digital image and the size it is printed at, will determine its resolution. Pixel dimensions also determine file size.
Adjusting the resolution and dimensions of image files
Incorrect image resolution is the most common error in customer submitted data. Follow these steps to get it right every time.
Color settings and color workflow
When designing for print, you are faced with the fundamental problem of viewing CMYK documents on RGB monitors. Calibrating your monitor correctly and creating a good color workflow are ways to ensure that what you see on screen is what you get back from the printing press are the same.